The A31/A32 alarm only applies to DC powered supply fans. If this alarm is displayed when the power supply for the fan is AC, change the fan setting SF1 in D menu from 0 to 1 or from AUT/DC to AC. If using the PGD, change option Ch1 in the Manufacturer Menu to AC. See the unit nameplate to determine supply fan power input.


An open signal between terminals 2 and 12 will trigger this alarm.


Single Phase AC Loss Troubleshooting


Possible Cause
Component to Check
Recommended Action
AC Loss
AC Breaker on units
Turn on breaker and make sure prime power is present to the unit
Power loss relay failure
Power relay (KA1)
If relay does not close when power is applied to the coil, replace the relay. 
Loose/incorrect alarm wire
Alarm wiring
Verify/tighten alarm wiring according to the Single Phase AC Loss Wiring diagram.


Single Phase AC Loss Wiring

 



Three Phase AC Loss Troubleshooting


Possible Cause
Component to Check
Recommended Action
AC Loss
AC Breaker on units
Turn on breaker and make sure prime power is present to the unit
Alarm present in Power/Phase MonitorPower/Phase Monitor (FV). Only the leftmost Normal LED should be lit.
•>U/<U LED indicates the voltage is outside the acceptable range (187-252V)
•Phs. Seq. LED indicates the phase sequence must be corrected
•Asm LED indicates the phases need to be balanced
Loose/incorrect alarm wire
Alarm wiring
Verify/tighten alarm wiring according to the Three Phase AC Loss Wiring diagram.


Three Phase AC Loss Wiring